Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 713
Filtrar
Más filtros

Tipo del documento
Intervalo de año de publicación
1.
Cell ; 173(5): 1179-1190.e13, 2018 05 17.
Artículo en Inglés | MEDLINE | ID: mdl-29775593

RESUMEN

Telomerase is an RNA-protein complex (RNP) that extends telomeric DNA at the 3' ends of chromosomes using its telomerase reverse transcriptase (TERT) and integral template-containing telomerase RNA (TER). Its activity is a critical determinant of human health, affecting aging, cancer, and stem cell renewal. Lack of atomic models of telomerase, particularly one with DNA bound, has limited our mechanistic understanding of telomeric DNA repeat synthesis. We report the 4.8 Å resolution cryoelectron microscopy structure of active Tetrahymena telomerase bound to telomeric DNA. The catalytic core is an intricately interlocked structure of TERT and TER, including a previously structurally uncharacterized TERT domain that interacts with the TEN domain to physically enclose TER and regulate activity. This complete structure of a telomerase catalytic core and its interactions with telomeric DNA from the template to telomere-interacting p50-TEB complex provides unanticipated insights into telomerase assembly and catalytic cycle and a new paradigm for a reverse transcriptase RNP.


Asunto(s)
ADN/metabolismo , Telomerasa/metabolismo , Telómero/metabolismo , Tetrahymena thermophila/metabolismo , Dominio Catalítico , Microscopía por Crioelectrón , ADN/química , Humanos , Modelos Moleculares , Conformación de Ácido Nucleico , Unión Proteica , Subunidades de Proteína/química , Subunidades de Proteína/metabolismo , Complejo Shelterina , Fosfatasa Ácida Tartratorresistente/metabolismo , Telomerasa/química , Telómero/química , Proteínas de Unión a Telómeros , Tetrahymena thermophila/enzimología
2.
Nature ; 608(7924): 813-818, 2022 08.
Artículo en Inglés | MEDLINE | ID: mdl-35831498

RESUMEN

Telomeres are the physical ends of linear chromosomes. They are composed of short repeating sequences (such as TTGGGG in the G-strand for Tetrahymena thermophila) of double-stranded DNA with a single-strand 3' overhang of the G-strand and, in humans, the six shelterin proteins: TPP1, POT1, TRF1, TRF2, RAP1 and TIN21,2. TPP1 and POT1 associate with the 3' overhang, with POT1 binding the G-strand3 and TPP1 (in complex with TIN24) recruiting telomerase via interaction with telomerase reverse transcriptase5 (TERT). The telomere DNA ends are replicated and maintained by telomerase6, for the G-strand, and subsequently DNA polymerase α-primase7,8 (PolαPrim), for the C-strand9. PolαPrim activity is stimulated by the heterotrimeric complex CTC1-STN1-TEN110-12 (CST), but the structural basis of the recruitment of PolαPrim and CST to telomere ends remains unknown. Here we report cryo-electron microscopy (cryo-EM) structures of Tetrahymena CST in the context of the telomerase holoenzyme, in both the absence and the presence of PolαPrim, and of PolαPrim alone. Tetrahymena Ctc1 binds telomerase subunit p50, a TPP1 orthologue, on a flexible Ctc1 binding motif revealed by cryo-EM and NMR spectroscopy. The PolαPrim polymerase subunit POLA1 binds Ctc1 and Stn1, and its interface with Ctc1 forms an entry port for G-strand DNA to the POLA1 active site. We thus provide a snapshot of four key components that are required for telomeric DNA synthesis in a single active complex-telomerase-core ribonucleoprotein, p50, CST and PolαPrim-that provides insights into the recruitment of CST and PolαPrim and the handoff between G-strand and C-strand synthesis.


Asunto(s)
ADN Primasa , Complejo Shelterina , Telomerasa , Tetrahymena , Microscopía por Crioelectrón , ADN/genética , ADN/metabolismo , ADN Primasa/química , ADN Primasa/metabolismo , ADN Primasa/ultraestructura , Holoenzimas/química , Holoenzimas/metabolismo , Holoenzimas/ultraestructura , Unión Proteica , Complejo Shelterina/química , Complejo Shelterina/metabolismo , Complejo Shelterina/ultraestructura , Telomerasa/química , Telomerasa/metabolismo , Telomerasa/ultraestructura , Telómero/genética , Telómero/metabolismo , Tetrahymena/química , Tetrahymena/enzimología , Tetrahymena/metabolismo , Tetrahymena/ultraestructura
3.
Am J Hum Genet ; 111(6): 1018-1034, 2024 Jun 06.
Artículo en Inglés | MEDLINE | ID: mdl-38749427

RESUMEN

Evolutionary changes in the hepatitis B virus (HBV) genome could reflect its adaptation to host-induced selective pressure. Leveraging paired human exome and ultra-deep HBV genome-sequencing data from 567 affected individuals with chronic hepatitis B, we comprehensively searched for the signatures of this evolutionary process by conducting "genome-to-genome" association tests between all human genetic variants and viral mutations. We identified significant associations between an East Asian-specific missense variant in the gene encoding the HBV entry receptor NTCP (rs2296651, NTCP S267F) and mutations within the receptor-binding region of HBV preS1. Through in silico modeling and in vitro preS1-NTCP binding assays, we observed that the associated HBV mutations are in proximity to the NTCP variant when bound and together partially increase binding affinity to NTCP S267F. Furthermore, we identified significant associations between HLA-A variation and viral mutations in HLA-A-restricted T cell epitopes. We used in silico binding prediction tools to evaluate the impact of the associated HBV mutations on HLA presentation and observed that mutations that result in weaker binding affinities to their cognate HLA alleles were enriched. Overall, our results suggest the emergence of HBV escape mutations that might alter the interaction between HBV PreS1 and its cellular receptor NTCP during viral entry into hepatocytes and confirm the role of HLA class I restriction in inducing HBV epitope variations.


Asunto(s)
Virus de la Hepatitis B , Mutación , Transportadores de Anión Orgánico Sodio-Dependiente , Simportadores , Humanos , Virus de la Hepatitis B/genética , Transportadores de Anión Orgánico Sodio-Dependiente/genética , Transportadores de Anión Orgánico Sodio-Dependiente/metabolismo , Simportadores/genética , Simportadores/metabolismo , Interacciones Huésped-Patógeno/genética , Interacciones Huésped-Patógeno/inmunología , Hepatitis B Crónica/virología , Hepatitis B Crónica/genética , Genoma Viral , Antígenos de Superficie de la Hepatitis B/genética , Epítopos de Linfocito T/genética , Epítopos de Linfocito T/inmunología , Genómica/métodos , Antígenos de Histocompatibilidad Clase I/genética , Antígenos de Histocompatibilidad Clase I/metabolismo
4.
Proc Natl Acad Sci U S A ; 120(44): e2304148120, 2023 Oct 31.
Artículo en Inglés | MEDLINE | ID: mdl-37844213

RESUMEN

Premelting of ice, a quasi-liquid layer (QLL) at the surface below the melting temperature, was first postulated by Michael Faraday 160 y ago. Since then, it has been extensively studied theoretically and experimentally through many techniques. Existing work has been performed predominantly on hexagonal ice, at conditions close to the triple point. Whether the same phenomenon can persist at much lower pressure and temperature, where stacking disordered ice sublimates directly into water vapor, remains unclear. Herein, we report direct observations of surface premelting on ice nanocrystals below the sublimation temperature using transmission electron microscopy (TEM). Similar to what has been reported on hexagonal ice, a QLL is found at the solid-vapor interface. It preferentially decorates certain facets, and its thickness increases as the phase transition temperature is approached. In situ TEM reveals strong diffusion of the QLL, while electron energy loss spectroscopy confirms its amorphous nature. More significantly, the premelting observed in this work is thought to be related to the metastable low-density ultraviscous water, instead of ambient liquid water as in the case of hexagonal ice. This opens a route to understand premelting and grassy liquid state, far away from the normal water triple point.

5.
J Infect Dis ; 2024 Feb 26.
Artículo en Inglés | MEDLINE | ID: mdl-38408366

RESUMEN

Chronic viral hepatitis is caused by hepatitis B virus, hepatitis C virus or hepatitis D virus (HBV, HCV, and HDV). Despite different replication strategies, all these viruses rely on secretion through the host endoplasmic reticulum-Golgi pathway, providing potential host targets for antiviral therapy. Knockdown of transmembrane 6 superfamily member 2 (TM6SF2) in virus cell culture models reduced secretion of infectious HCV virions, HDV virions and HBV subviral particles. Moreover, in a cohort of people with hepatitis B a TM6SF2 polymorphism (rs58542926 CT/TT, which causes protein misfolding and reduced TM6SF2 in the liver) correlated with lower concentrations of subviral particles in blood, complementing our previous work showing decreased HCV viral load in people with this polymorphism. In conclusion, the host protein TM6SF2 plays a key role in secretion of HBV, HCV and HDV, providing the potential for novel pan-viral agents to treat people with chronic viral hepatitis.

6.
J Hepatol ; 80(4): 553-563, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38101755

RESUMEN

BACKGROUND & AIMS: The use of tenofovir disoproxil fumarate (TDF) is associated with a reduction in bone mineral density and an increase in bone metabolism biomarkers. However, data on clinical bone fractures remain limited. We evaluated the impact of TDF compared to entecavir on the risk of fracture in elderly patients with chronic hepatitis B (CHB). METHODS: Patients with CHB aged ≥60 years receiving entecavir or TDF between January 2008 and December 2022 were identified using a territory-wide database in Hong Kong. The risk of incident fracture in entecavir- and TDF-treated patients before and after month 24 were compared after propensity score matching. RESULTS: A total of 41,531 patients with CHB (mean age 69.8±7.8 years, 61.6% male) receiving entecavir (n = 39,897 [96.1%]) and TDF (n = 1,634 [3.9%]) were analysed. At a median follow-up of 25.3 (9.1-58.5) months, 1,733 (4.2%) patients developed incident fracture. Patients with incident fracture were more likely to have diabetes, hypertension, congestive heart failure, rheumatoid arthritis, osteoporosis, and a history of fracture. Compared with propensity score-matched entecavir-treated patients, the risk of incident fracture in TDF-treated patients was comparable in the first 24 months (weighted subdistribution hazard ratio [sHR] 0.99, 95% CI 0.56-1.73, p = 0.960) but increased after month 24 (weighted sHR 1.80, 95% CI 1.11-2.93, p = 0.019). The 24-, 60-, and 96-month cumulative incidences (95% CI) of fracture in TDF-treated and entecavir-treated patients were 2.3% (1.6%-3.4%) vs. 2.6% (1.9%-3.5%), 6.4% (5.0%-8.2%) vs. 4.7% (3.8%-6.0%), and 10.2% (8.3%-12.6%) vs. 6.8% (5.4%-8.5%), respectively. CONCLUSIONS: The risk of fracture increased with TDF treatment for ≥24 months in elderly patients with CHB. Selection of nucleos(t)ide analogues should be individualised based on age and comorbidities. IMPACT AND IMPLICATIONS: Previous literature suggested that the use of tenofovir disoproxil fumarate (TDF) is associated with a decrease in bone mineral density. However, data on the impact of TDF on long-term incident clinical fracture remains scarce. In this real-world territory-wide study of 41,531 treated patients with chronic hepatitis B in Hong Kong, patients who received TDF were at a higher risk of fracture after 2 years of treatment than those who received entecavir. Given the ageing population of patients with chronic hepatitis B and the rising prevalence of comorbidities, our findings support the current treatment guidelines that recommend selecting antiviral treatment based on age and comorbidities.


Asunto(s)
Fracturas Óseas , Hepatitis B Crónica , Anciano , Humanos , Masculino , Persona de Mediana Edad , Femenino , Tenofovir/efectos adversos , Hepatitis B Crónica/complicaciones , Hepatitis B Crónica/tratamiento farmacológico , Antivirales/efectos adversos , Estudios Retrospectivos , Resultado del Tratamiento , Fracturas Óseas/inducido químicamente , Fracturas Óseas/epidemiología , Fracturas Óseas/complicaciones
7.
Clin Gastroenterol Hepatol ; 22(3): 602-610.e7, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-37993034

RESUMEN

BACKGROUND & AIMS: The existing hepatocellular carcinoma (HCC) risk scores have modest accuracy, and most are specific to chronic hepatitis B infection. In this study, we developed and validated a liver stiffness-based machine learning algorithm (ML) for prediction and risk stratification of HCC in various chronic liver diseases (CLDs). METHODS: MLs were trained for prediction of HCC in 5155 adult patients with various CLDs in Korea and further tested in 2 prospective cohorts from Hong Kong (HK) (N = 2732) and Europe (N = 2384). Model performance was assessed according to Harrell's C-index and time-dependent receiver operating characteristic (ROC) curve. RESULTS: We developed the SMART-HCC score, a liver stiffness-based ML HCC risk score, with liver stiffness measurement ranked as the most important among 9 clinical features. The Harrell's C-index of the SMART-HCC score in HK and Europe validation cohorts were 0.89 (95% confidence interval, 0.85-0.92) and 0.91 (95% confidence interval, 0.87-0.95), respectively. The area under ROC curves of the SMART-HCC score for HCC in 5 years was ≥0.89 in both validation cohorts. The performance of SMART-HCC score was significantly better than existing HCC risk scores including aMAP score, Toronto HCC risk index, and 7 hepatitis B-related risk scores. Using dual cutoffs of 0.043 and 0.080, the annual HCC incidence was 0.09%-0.11% for low-risk group and 2.54%-4.64% for high-risk group in the HK and Europe validation cohorts. CONCLUSIONS: The SMART-HCC score is a useful machine learning-based tool for clinicians to stratify HCC risk in patients with CLDs.


Asunto(s)
Carcinoma Hepatocelular , Hepatitis B Crónica , Hepatitis B , Neoplasias Hepáticas , Adulto , Humanos , Carcinoma Hepatocelular/epidemiología , Neoplasias Hepáticas/epidemiología , Estudios Prospectivos , Factores de Riesgo , Hepatitis B Crónica/tratamiento farmacológico , Algoritmos , Aprendizaje Automático , Hepatitis B/complicaciones , Cirrosis Hepática/complicaciones , Cirrosis Hepática/diagnóstico , Cirrosis Hepática/tratamiento farmacológico , Antivirales/uso terapéutico
8.
Am J Gastroenterol ; 2024 Apr 22.
Artículo en Inglés | MEDLINE | ID: mdl-38483300

RESUMEN

INTRODUCTION: Complete viral suppression with nucleos(t)ide analogs (NAs) has led to a profound reduction in hepatocellular carcinoma and mortality among patients with chronic hepatitis B. Finite therapy yields higher rates of functional cure; however, initial hepatitis B virus (HBV) DNA and alanine aminotransferase (ALT) elevations are almost certain after treatment interruption. We aimed to analyze off-treatment outcomes beyond 12 months after NA cessation. METHODS: Patients with well-suppressed chronic hepatitis B who were hepatitis B e antigen-negative at NA cessation and remained off treatment without hepatitis B surface antigen (HBsAg) loss at 12 months were included (n = 945). HBV DNA and ALT fluctuations were allowed within the first 12 months. We used Kaplan-Meier methods to analyze outcomes beyond 12 months. Sustained remission was defined as HBV DNA <2,000 IU/mL and ALT <2× upper limit of normal (ULN) and an ALT flare as ALT ≥5× ULN. RESULTS: Cumulative probability of sustained remission was 29.7%, virological relapse was 65.2% with a mean peak HBV DNA of 5.0 ± 1.5 log 10 IU/mL, an ALT flare was 15.6% with a median peak ALT × ULN of 8.3 (5.7-11.3), HBsAg loss was 9.9% and retreatment was 34.9% at 48 months after NA cessation. A single occurrence of virological relapse or an ALT flare within the first 12 months off-treatment were associated with significantly lower rates of sustained remission beyond 12 months. DISCUSSION: Despite allowing for HBV DNA and ALT fluctuations within the first 12 months off-treatment, most patients without HBsAg loss did not maintain a sustained response thereafter. The best candidates for NA withdrawal are patients with low HBsAg levels at NA cessation, and those without profound or recurrent virological and biochemical relapses in the first off-treatment year.

9.
Hepatology ; 77(2): 573-584, 2023 02 01.
Artículo en Inglés | MEDLINE | ID: mdl-35790018

RESUMEN

BACKGROUND AND AIMS: It is unclear if the leading causes of death in patients with NAFLD differ by age. We aimed to investigate if the relative importance of liver-related deaths is lower and overshadowed by cardiovascular and cancer-related deaths in the elderly population. APPROACH AND RESULTS: We conducted a territory-wide retrospective cohort study of adult patients with NAFLD between 2000 and 2021 in Hong Kong. The outcomes of interest were all-cause and cause-specific mortality. Age groups at death were studied at 10-year intervals. During 662,471 person-years of follow-up of 30,943 patients with NAFLD, there were 2097 deaths. The top three causes of death were pneumonia, extrahepatic cancer, and cardiovascular diseases. Liver disease was the sixth leading cause of death in patients aged 70-79 and 80-89 years, accounting for 5.1% and 5.9% of deaths, respectively, but only accounted for 3% or fewer of the deaths in the other age groups. Nonetheless, liver disease was the leading cause of death in patients with NAFLD-related cirrhosis, accounting for 36.8% of all deaths. The incidence of liver-related death was higher in men younger than age 70 but higher in women afterwards. The incidence of liver-related death in women increased from 0.62 to 7.14 per 10,000 person-years from age 60-69 to 70-79 years. CONCLUSION: The relative importance of liver-related death increases with age in patients with NAFLD, especially among women. In patients with cirrhosis, liver disease is the leading cause of death.


Asunto(s)
Neoplasias , Enfermedad del Hígado Graso no Alcohólico , Adulto , Masculino , Humanos , Anciano , Femenino , Enfermedad del Hígado Graso no Alcohólico/complicaciones , Estudios Retrospectivos , Cirrosis Hepática/etiología
10.
Hepatology ; 78(6): 1816-1827, 2023 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-37119179

RESUMEN

BACKGROUND AND AIMS: We aimed to determine the impact of the duration of type 2 diabetes (T2D) on the risk of liver-related events and all-cause mortality in patients with NAFLD. APPROACH AND RESULTS: We conducted a territory-wide cohort study of adult patients with NAFLD diagnosed between January 1, 2000, and July 31, 2021, in Hong Kong. T2D was defined by the use of any antidiabetic agents, laboratory tests, and/or diagnosis codes. The primary endpoint was liver-related events, defined as a composite endpoint of HCC and cirrhotic complications. To conduct a more granular assessment of the duration of T2D, we employed landmark analysis in four different ages of interest (biological age of 40, 50, 60, and 70 years). By multivariable analysis with adjustment of non-liver-related deaths, compared with patients without diabetes at age 60 (incidence rate of liver-related events: 0.70 per 1,000 person-years), the adjusted subdistribution HR (SHR) of liver-related events was 2.51 (95% CI: 1.32-4.77; incidence rate: 2.26 per 1,000 person-years) in patients with T2D duration < 5 years, 3.16 (95% CI: 1.59-6.31; incidence rate: 2.54 per 1,000 person-years) in those with T2D duration of 6-10 years, and 6.20 (95% CI: 2.62-14.65; incidence rate: 4.17 per 1000 person-years) in those with T2D duration more than 10 years. A similar association between the duration of T2D and all-cause mortality was also observed. CONCLUSIONS: Longer duration of T2D is significantly associated with a higher risk of liver-related events and all-cause mortality in patients with NAFLD.


Asunto(s)
Carcinoma Hepatocelular , Diabetes Mellitus Tipo 2 , Neoplasias Hepáticas , Enfermedad del Hígado Graso no Alcohólico , Adulto , Humanos , Persona de Mediana Edad , Diabetes Mellitus Tipo 2/complicaciones , Diabetes Mellitus Tipo 2/epidemiología , Enfermedad del Hígado Graso no Alcohólico/complicaciones , Enfermedad del Hígado Graso no Alcohólico/epidemiología , Estudios de Cohortes , Carcinoma Hepatocelular/complicaciones , Neoplasias Hepáticas/complicaciones , Factores de Riesgo
11.
Liver Int ; 2024 Jul 05.
Artículo en Inglés | MEDLINE | ID: mdl-38967425

RESUMEN

BACKGROUND AND AIMS: Mother-to-child-transmission (MTCT) of hepatitis B virus (HBV) may still occur despite birth-dose HBV vaccinations when pregnant women are positive for hepatitis B surface antigen (HBsAg) with high viral loads (HBV DNA ≥ 200 000 IU/mL). A pilot integrated model nurse clinic (IMNC) was started in 2020 to implement the pre-emptive antiviral therapy with tenofovir disoproxil fumarate (TDF). We aimed to evaluate the performance of IMNC on uptake of TDF. METHODS: This was a territory-wide retrospective cohort of all consecutive HBsAg-positive women of child-bearing age with pregnancy records in public hospitals 2019-2022. Demographic characteristics, liver biochemistries and virologic parameters, and TDF use were collected. Concurrently, data from a prospective audit in Union Hospital, the private hospital with the highest number of deliveries in Hong Kong, from June 2022 to May 2023 were compared. RESULTS: The prevalence rate of HBV DNA ≥ 200 000 IU/mL in pregnant women with available HBV DNA records was 29.2% (66/226) in 2019, 27.3% (99/363) in 2020, 15.9% (125/784) in 2021 and 17.2% (117/679) in 2022 (p < .001), out of 2052 pregnant women who had their HBV DNA checked within 1 year prior to delivery. An increasing uptake rate of TDF by highly viraemic pregnant women (i.e. ≥ 200 000 IU/mL) was noted after the commencement of IMNC in public hospitals, with 67% (45/67) in 2019, 83% (88/106) in 2020, 91% (117/128) in 2021 and 89% (149/167) in 2022. Moreover, all highly viraemic pregnant women from Union Hospital received TDF. Continuous use of TDF was associated with a reduced risk of postpartum biochemical flare. CONCLUSIONS: IMNC increases the uptake of antiviral treatment in pregnant women at risk of MTCT of HBV. IMNC contributes to hepatitis elimination through a structured care plan to prevent MTCT of HBV.

12.
J Phys Chem A ; 2024 Jun 13.
Artículo en Inglés | MEDLINE | ID: mdl-38872347

RESUMEN

Arsenene, a less-explored two-dimensional material, holds the potential for applications in wearable electronics, memory devices, and quantum systems. This study introduces a bond-order potential model with Tersoff formalism, the ML-Tersoff, which leverages multireward hierarchical reinforcement learning (RL), trained on an ab initio data set. This data set covers a spectrum of properties for arsenene polymorphs, enhancing our understanding of its mechanical and thermal behaviors without the complexities of traditional models requiring multiple parameter sets. Our RL strategy utilizes decision trees coupled with a hierarchical reward strategy to accelerate convergence in high-dimensional continuous search spaces. Unlike the Stillinger-Weber approach, which demands separate formalisms for buckled and puckered forms, the ML-Tersoff model concurrently captures multiple properties of the two polymorphs by effectively representing the local environment, thereby avoiding the need for different atomic types. We apply the ML model to understand the mechanical and thermal properties of the arsenene polymorphs and nanostructures. We observe an inverse relationship between the critical strain and temperature in arsenene. Thermal conductivity calculations in nanosheets show good agreement with ab initio data, reflecting a decrease in thermal conductivity attributable to increased anharmonic effects at higher temperatures. We also apply the model to predict the thermal behavior of arsenene nanotubes.

13.
Lasers Surg Med ; 56(4): 404-418, 2024 04.
Artículo en Inglés | MEDLINE | ID: mdl-38436524

RESUMEN

BACKGROUND AND OBJECTIVES: A threshold fluence for melanosome disruption has the potential to provide a robust numerical indicator for establishing clinical endpoints for pigmented lesion treatment using a picosecond laser. Although the thresholds for a 755-nm picosecond laser were previously reported, the wavelength dependence has not been investigated. In this study, wavelength-dependent threshold fluences for melanosome disruption were determined. Using a mathematical model based on the thresholds, irradiation parameters for 532-, 730-, 755-, 785-, and 1064-nm picosecond laser treatments were evaluated quantitatively. STUDY DESIGN/MATERIALS AND METHODS: A suspension of melanosomes extracted from porcine eyes was irradiated using picosecond lasers with varying fluence. The mean particle size of the irradiated melanosomes was measured by dynamic light scattering, and their disruption was observed by scanning electron microscopy to determine the disruption thresholds. A mathematical model was developed, combined with the threshold obtained and Monte Carlo light transport to calculate irradiation parameters required to disrupt melanosomes within the skin tissue. RESULTS: The threshold fluences were determined to be 0.95, 2.25, 2.75, and 6.50 J/cm² for 532-, 730-, 785-, and 1064-nm picosecond lasers, respectively. The numerical results quantitatively revealed the relationship between irradiation wavelength, incident fluence, and spot size required to disrupt melanosomes distributed at different depths in the skin tissue. The calculated irradiation parameters were consistent with clinical parameters that showed high efficacy with a low incidence of complications. CONCLUSION: The wavelength-dependent thresholds for melanosome disruption were determined. The results of the evaluation of irradiation parameters from the threshold-based analysis provided numerical indicators for setting the clinical endpoints for 532-, 730-, 755-, 785-, and 1064-nm picosecond lasers.


Asunto(s)
Láseres de Estado Sólido , Melanosomas , Animales , Porcinos , Melanosomas/efectos de la radiación , Rayos Láser , Piel/efectos de la radiación , Láseres de Estado Sólido/uso terapéutico , Resultado del Tratamiento
14.
Lasers Surg Med ; 56(2): 142-149, 2024 02.
Artículo en Inglés | MEDLINE | ID: mdl-38247054

RESUMEN

BACKGROUND AND OBJECTIVES: Fractional radiofrequency devices have been demonstrated to improve skin texture, such as smoothness, rhytides, brightness, and atrophic acne scars, by increasing dermal thickness, dermal collagen content, and dermal fibrillin content. The objective of the study is to assess the efficacy and adverse effects of this device on Asian patients of skin type III and IV with skin textural changes. MATERIALS AND METHODS: The study was designed as a prospective, open-labeled single-arm study, which was conducted with 20 Chinese patients aged 21-60 years and having irregularities in their skin texture, rhytides, and acne scars. The patients received six treatments at intervals of 4 weeks. Treatment was initiated with the maximum energy tolerated, which was then adjusted during the course of treatment if the patients felt excessive discomfort. A total of two passes were delivered in each session. Physician assessment results and standardized photographs were collected at the baseline, after all treatment visits, and at 1, 2, and 6 months after the final treatment visit. RESULTS: A total of 17 patients completed the study according to the established protocol. At the 6-month follow-up, 71% of patients were satisfied and 24% of patients were very satisfied with the received treatments, and the treatment physician reported varying degrees of improvement based on the global assessment scale in 60% of the subjects. While the anticipated side effects, such as erythema, edema, pinpoint bleeding, scab formation, and flare of acne, were noted in the patients, no serious adverse effects occurred. CONCLUSION: The use of fractional radiofrequency improves skin texture and is safe for use in Asian patients of skin type III and IV. No long-term serious adverse effects were noted.


Asunto(s)
Acné Vulgar , Cicatriz , Humanos , Acné Vulgar/radioterapia , Pueblo Asiatico , Cicatriz/terapia , Estudios Prospectivos , Piel/patología , Resultado del Tratamiento , Adulto Joven , Adulto , Persona de Mediana Edad
15.
Lasers Surg Med ; 2024 Jun 23.
Artículo en Inglés | MEDLINE | ID: mdl-38922979

RESUMEN

OBJECTIVE: Our study aimed to evaluate the efficacy of this novel dermal cooling system (DCS) in reducing pigmentation in benign pigmented lesions in Asian patients and its potential side effects. METHODS: It was a prospective open-label single-center study. Asian patients, with the presence of benign pigmented lesions mainly including lentigines, melasma, nevus spilus, ephelides, café au lait, and seborrheic keratosis were recruited for a novel DCS. The DCS provided localized cooling of the epidermal layer below freezing but was less intense than cryotherapy. Each patient received DCS at Week 0 and repeated at 4-week intervals up to 10 sessions. Global aesthetic improvement scores (GAIS) by blinded physicians and subjects were recorded at 2, 6, and 12 months posttreatment follow-up. RESULTS: Eighty-one patients were recruited with a total of 305 sessions performed and 1716 lesion sites treated. At 2-month posttreatment, 76.5% and 58.6% treatment sites showed obvious to marked improvement respectively and the improvement sustained at 6 and 12 months. Only minor adverse events were reported. Erythema and edema were the most commonly anticipated effects immediately after treatment. The pain was minimal. Postinflammatory hyperpigmentation was only reported in 2.2% (38/1716) treated sites. CONCLUSION: To our knowledge, this study was the first study to demonstrate that this novel DCS was an effective, safe, and well-tolerated treatment for benign pigmented lesions in Asians.

16.
Gut ; 72(12): 2364-2371, 2023 Nov 24.
Artículo en Inglés | MEDLINE | ID: mdl-37549979

RESUMEN

OBJECTIVE: We aimed to test the hypothesis that automated fibrosis score calculation and electronic reminder messages could increase the detection of advanced liver disease in patients with type 2 diabetes. DESIGN: In this pragmatic randomised controlled trial at five general medical or diabetes clinics in Hong Kong and Malaysia, we randomly assigned patients in a 1:1 ratio to the intervention group with Fibrosis-4 index and aspartate aminotransferase-to-platelet ratio index automatically calculated based on routine blood tests, followed by electronic reminder messages to alert clinicians of abnormal results, or the control group with usual care. The primary outcome was the proportion of patients with increased fibrosis scores who received appropriate care (referred for hepatology care or specific fibrosis assessment) within 1 year. RESULTS: Between May 2020 and Oct 2021, 1379 patients were screened, of whom 533 and 528 were assigned to the intervention and control groups, respectively. A total of 55 out of 165 (33.3%) patients with increased fibrosis scores in the intervention group received appropriate care, compared with 4 of 131 (3.1%) patients in the control group (difference 30.2% (95% CI 22.4% to 38%); p<0.001). Overall, 11 out of 533 (2.1%) patients in the intervention group and 1 out of 528 (0.2%) patients in the control group were confirmed to have advanced liver disease (difference 1.9% (95% CI 0.61% to 3.5%); p=0.006). CONCLUSION: Automated fibrosis score calculation and electronic reminders can increase referral of patients with type 2 diabetes and abnormal fibrosis scores at non-hepatology settings. TRIAL REGISTRATION NUMBER: NCT04241575.


Asunto(s)
Diabetes Mellitus Tipo 2 , Enfermedades del Sistema Digestivo , Hepatopatías , Enfermedad del Hígado Graso no Alcohólico , Humanos , Diabetes Mellitus Tipo 2/complicaciones , Diabetes Mellitus Tipo 2/diagnóstico , Diabetes Mellitus Tipo 2/terapia , Vías Clínicas , Fibrosis , Cirrosis Hepática/diagnóstico
17.
Gut ; 72(7): 1385-1398, 2023 07.
Artículo en Inglés | MEDLINE | ID: mdl-36697207

RESUMEN

OBJECTIVE: We present the final analysis results of the phase 2 JADE study (ClinicalTrials.gov Identifier: NCT03361956). DESIGN: 232 patients with chronic hepatitis B (CHB) not currently treated at study start (NCT) at study start or virologically suppressed were randomised to receive 75 mg (part 1) or 250 mg (part 2) JNJ-56136379, a hepatitis B virus (HBV)-capsid assembly modulator, one time per day or placebo with nucleos(t)ide analogue (NA) (tenofovir disoproxil fumarate/entecavir) or JNJ-56136379 alone (NCT-only) for ≥24 and ≤48 weeks. RESULTS: In patients who are NCT hepatitis B e-antigen (HBeAg) positive, JNJ-56136379 75 mg+NA and 250 mg+NA showed limited mean (SE) hepatitis B surface antigen (HBsAg) declines (0.14 (0.10) and 0.41 (0.15), respectively) from baseline at Week 24 (primary endpoint; placebo+NA: 0.25 (0.11) log10 international unit (IU)/mL).In patients who are NCT HBeAg positive, mean (SE) HBV DNA declines at Week 24 were 5.53 (0.23) and 5.88 (0.34) for JNJ-56136379 75 mg+NA and 250 mg+NA, respectively, versus 5.21 (0.42) log10 IU/mL for placebo+NA. In NCT patients, mean (SE) HBV RNA declines were 2.96 (0.23) and 3.15 (0.33) versus 1.33 (0.32) log10 copies/mL, respectively.Patients with HBsAg declines had HBeAg and hepatitis B core-related antigen (HBcrAg) declines and some early on-treatment isolated alanine aminotransferase flares. Viral breakthrough occurred with JNJ-56136379 monotherapy with the emerging resistant-variant T33N, but not with JNJ-56136379+NA. JNJ-56136379 treatment beyond Week 24 had a generally small additional effect on viral markers.No study treatment-related serious adverse events or clinically significant changes in laboratory parameters occurred. CONCLUSIONS: In patients with non-cirrhotic CHB, JNJ-56136379+NA showed pronounced reductions in HBV DNA and HBV RNA, limited HBsAg or HBeAg declines in patients who are NCT HBeAg positive, and was well tolerated, but no clear benefit with regards to efficacy of JNJ-56136379 over NA was observed.


Asunto(s)
Hepatitis B Crónica , Hepatitis B , Humanos , Virus de la Hepatitis B/genética , Antígenos de Superficie de la Hepatitis B , Antivirales/efectos adversos , Antígenos e de la Hepatitis B , Cápside/química , ADN Viral/análisis , Antígenos del Núcleo de la Hepatitis B , Resultado del Tratamiento
18.
Clin Infect Dis ; 76(3): e26-e33, 2023 02 08.
Artículo en Inglés | MEDLINE | ID: mdl-36031408

RESUMEN

BACKGROUND: We examined the effectiveness of molnupiravir and nirmatrelvir/ritonavir in reducing hospitalization and deaths in a real-world cohort of nonhospitalized patients with coronavirus disease 2019 (COVID-19). METHODS: This was a territory-wide retrospective cohort study in Hong Kong. Nonhospitalized COVID-19 patients who attended designated outpatient clinics between 16 February and 31 March 2022 were identified. Patients hospitalized on the day of the first clinic appointment or used both oral antivirals were excluded. The primary endpoint was hospitalization. The secondary endpoint was a composite of intensive care unit admission, invasive mechanical ventilation use, and/or death. RESULTS: Of 93 883 patients, 83 154 (88.6%), 5808 (6.2%), and 4921 (5.2%) were oral antiviral nonusers, molnupiravir users, and nirmatrelvir/ritonavir users, respectively. Compared with nonusers, oral antiviral users were older and had more comorbidities, lower complete vaccination rate, and more hospitalizations in the previous year. Molnupiravir users were older and had more comorbidities, lower complete vaccination rate, and more hospitalizations in the previous year than nirmatrelvir/ritonavir users. At a median follow-up of 30 days, 1931 (2.1%) patients were hospitalized and 225 (0.2%) patients developed the secondary endpoint. After propensity score weighting, nirmatrelvir/ritonavir use (weighted hazard ratio 0.79; 95% confidence interval [CI], 0.65-0.95; P = .011) but not molnupiravir use (weighted hazard ratio 1.17; 95% CI, 0.99-1.39; P = .062) was associated with a reduced risk of hospitalization than nonusers. The use of molnupiravir or nirmatrelvir/ritonavir was not associated with a lower risk of the secondary endpoint as compared with nonusers. CONCLUSION: Use of nirmatrelvir/ritonavir but not molnupiravir was associated with a reduced risk of hospitalization in real-world nonhospitalized patients with COVID-19.


Asunto(s)
COVID-19 , Humanos , Estudios Retrospectivos , Antivirales/uso terapéutico , Hospitalización
19.
J Hepatol ; 78(3): 524-533, 2023 03.
Artículo en Inglés | MEDLINE | ID: mdl-36463985

RESUMEN

BACKGROUND & AIMS: We examined the long-term incidence of hepatocellular carcinoma (HCC) and hepatic decompensation among chronic hepatitis B (CHB) patients who have achieved hepatitis B surface antigen (HBsAg) seroclearance. METHODS: All adult CHB-monoinfected patients who cleared HBsAg between January 2000 and December 2020 were identified using a territory-wide database in Hong Kong. Patients who underwent liver transplantation and/or developed HCC before HBsAg seroclearance or less than 6 months follow-up were excluded. The primary and secondary endpoints were HCC and hepatic decompensation respectively. RESULTS: We identified 9,769 patients with CHB who achieved HBsAg seroclearance (mean age 57 years, 60.0% male, 13.2% cirrhosis); most had compensated liver function at HBsAg loss. At a median (25th-75th percentile) follow-up of 4.6 (2.2-8.4) years, 106 (1.1%) patients developed HCC. Patients who developed HCC were older, more likely to be male and have cirrhosis, and had higher alanine aminotransferase and lower platelets at the time of HBsAg loss than patients without HCC. The cumulative incidence of HCC remained steady 0-7 and 8-12 years after HBsAg loss (p = 0.898) (crude annual incidence drop: -0.04%, 95% CI -0.13% to 0.04%, p = 0.265). Moreover, 124/9,640 (1.3%) patients developed hepatic decompensation. The growth in cumulative incidence of hepatic decompensation decelerated 8-12 years after HBsAg loss (p = 0.009) (crude annual incidence drop: -0.23%, 95% CI -0.40% to -0.06%, p = 0.012). In multivariable analysis, HBsAg loss for over 7 years was associated with a reduced risk of hepatic decompensation (adjusted subdistribution hazard ratio [aSHR] 0.55, 95% CI 0.31-0.97, p = 0.039) but not HCC (aSHR 1.35, 95% CI 0.83-2.19, p = 0.230). CONCLUSION: HCC risk persists in patients after HBsAg loss, whereas the risk of hepatic decompensation decreases over time. IMPACT AND IMPLICATIONS: Patients with chronic hepatitis B (CHB) still have a non-negligible risk of hepatocellular carcinoma (HCC) after 12 years of HBsAg seroclearance, especially among those with cirrhosis. The risk of developing hepatic decompensation decreases over time after HBsAg seroclearance. In clinical practice, although patients with CHB who cleared HBsAg have a more favourable clinical outcome than those who remain chronically infected, long-term HCC surveillance would still be necessary for patients with cirrhosis and other high-risk subgroups after HBsAg seroclearance.


Asunto(s)
Carcinoma Hepatocelular , Hepatitis B Crónica , Neoplasias Hepáticas , Adulto , Humanos , Masculino , Persona de Mediana Edad , Femenino , Antígenos de Superficie de la Hepatitis B , Neoplasias Hepáticas/patología , Carcinoma Hepatocelular/patología , Cirrosis Hepática/complicaciones , Virus de la Hepatitis B/genética , ADN Viral
20.
Clin Gastroenterol Hepatol ; 21(11): 2864-2875.e16, 2023 10.
Artículo en Inglés | MEDLINE | ID: mdl-36828301

RESUMEN

BACKGROUND & AIMS: We examined whether changing clinical characteristics and presence of diabetes mellitus (DM) impact the performance of hepatocellular carcinoma (HCC) risk scores. METHODS: Adult patients with chronic hepatitis B (CHB) on ≥6 months of entecavir/tenofovir treatment between January 2005 and March 2020 were identified using a territory-wide electronic database in Hong Kong. DM was defined by antidiabetic agents, hemoglobin A1c ≥6.5%, fasting glucose ≥7 mmol/L, and/or diagnosis codes. PAGE-B, modified PAGE-B (mPAGE-B), and aMAP scores were assessed by area under the time-dependent receiver operating characteristic curves (AUROCs) and compared with CAMD and REAL-B scores with DM as a component. RESULTS: Of 48,706 patients, 2792, 11,563, 15,471, and 18,880 started entecavir/tenofovir treatment between 2005-2008, 2009-2012, 2013-2016, and 2017-2020, respectively; DM prevalence rose from 15.5% in 2005-2008 to 24.3% in 2017-2020. AUROCs were comparable across the 4 periods in the 5 HCC risk scores (AUROCs ranged between 0.75 and 0.81). At a median follow-up of 4.4 years, 1512 non-diabetic (4.0%) and 645 (6.2%) diabetic patients developed HCC. AUROCs of all 5 scores were lower in diabetic patients than in non-diabetic patients (AUROCs ranged between 0.67-0.71 vs 0.78-0.82; all P < .001). REAL-B score achieved an AUROC of 0.71 in diabetic and 0.82 in non-diabetic patients. Both diabetic and non-diabetic patients in the low-risk group by REAL-B score had a low HCC incidence below the threshold of cost-effective HCC surveillance, ie, 0.2% annually. CONCLUSIONS: REAL-B score is accurate and preferred in entecavir/tenofovir-treated CHB patients because of the increasing prevalence of DM.


Asunto(s)
Carcinoma Hepatocelular , Diabetes Mellitus , Hepatitis B Crónica , Neoplasias Hepáticas , Adulto , Humanos , Carcinoma Hepatocelular/epidemiología , Carcinoma Hepatocelular/etiología , Carcinoma Hepatocelular/diagnóstico , Neoplasias Hepáticas/epidemiología , Neoplasias Hepáticas/etiología , Neoplasias Hepáticas/diagnóstico , Antivirales/uso terapéutico , Hepatitis B Crónica/complicaciones , Hepatitis B Crónica/tratamiento farmacológico , Hepatitis B Crónica/diagnóstico , Tenofovir/uso terapéutico , Factores de Riesgo , Diabetes Mellitus/epidemiología
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA